Sulli and Jay are fraternal twins who could pass off as identical twins. What happens when the mischievous Jay asks his sister to disguise herself as him to attend boarding school while he goes off to attend a dance competition in London? Trouble! What awaits Sulli as she figures out that her roommate is her sports idol, the famous high school soccer player Choi Minho?  

Engaged at birth by both families, Minho and Sulli have always looked out, cared, and loved each other since childhood. Promising to never leave his side, Sulli (18) leaves home for the first time to the United States and leaves a heartbroken Minho alone on his 21st birthday wondering what he had done wrong to ruin their perfect relationship. 4 years later she returns to Seoul as his hotel business partner and finds an arrogant, cold and unfamiliar Minho. Will they find their way back to ea